Patent GB-409776-A (GB)
Title: Improvements in or relating to remote control and/or supervisory systems
IPC: H02J13/00
Filed: 1932-11-10
Abstract: 409,776. Electric signalling and distant-control systems. AUTOMATIC ELECTRIC CO., Ltd., Strowger Works, Liverpool, RAYNER, T. R., 2, Stretton Avenue, Wallasey, Cheshire, and GUNNING, P. F., 10, Fairfield Street, Fairfield, Liverpool. Nov. 10, 1932, No. 31866. [Class 40 (i).] Relates to remote control or supervisory systems for use on electric power supply systems whereby substantially simultaneous tripping of two circuit-breakers controlling a section of the system is effected. According to the invention, a circuit-breaker on changing its position or condition initiates the transmission of a characteristic signal to an associated breaker to effect a corresponding change in the position or condition thereof. The signal clears the signalling line of other types of transmission, and comprises a simultaneous transmission of three frequencies, followed by a series of transmissions in which each frequency is omitted in turn, for selecting the particular breaker, followed by a repetition of the simultaneous transmission for tripping the breaker In Fig. 1, power stations A .. D having identity frequencies as shown are connected to a central indicating station CIS and B .. D are adjacent and connected by a power line shown dotted. When a fault occurs between B, C and the breaker at B trips, the three frequencies are applied simultaneously to the control line, CIS responds and connects AB line to CD line over repeater R. If A happens to be signalling at the time, its signalling circuit is cut off by a guard circuit responsive to the three frequencies, but is left in condition to resume when the intertrip signal has passed. The arrangement is further such that a station cannot butt in on a signalling operation that is in progress unless it is for intertripping purposes. CIS is shown in Figs. 2, 3, 7, 8 and the sending and receiving equipment of a station, say B, in Figs. 4, 5, 6. When CB1 of station B, Fig. 6, trips, relay SA is energized by transmitcontacts, locks over sa1 and at sa3 shorts relay N to prevent it from changing the code. sa2 makes a circuit for SND and another over 10 for cut-off relay CO, which at col disconnects controlling earth from normal supervision circuit of B, energizes T, TCO, and at co2, co3 operates relay S which locks over s1 to prepare for restarting of normal supervision after intertripping conditions are over. T at t1, t2 disconnects signal relays IH, IM which respond to high and medium frequencies, whereas TCO at tcol, tco2 changes over the line from high-pass filter 'phone circuit to high and medium frequency receivers and oscillators and low oscillator. Station B is now ready for SND to cause operation of transmit relays SHF, SMF, SLF which in turn connect the necessary oscillators (Fig. 4), SND being so wired to SHF &c. as to send code No. 1 (Fig. 6). The step-by-step movement of wipers 1a .. 5a is effectedly relay IMP, in series with contacts snm and driving magnet SNM, shorting itself at imp1 and energizing SNM sufficiently to operate it. At CIS, the low receiver attracts low A, making over 11<a> circuit for receiving relay LR, also armatures cr1, cr2 change the line from 'phone circuit to high and medium receivers and oscillators and low oscillator. High and medium receivers, in responding, energize HR, MR, Fig. 2, which make circuits over mrl, hrl for cut-off relays ICO, COR which operate to clear the normal signal equipment and prepare for repeating the intertrip signal by operation of SR in lines 1, 2. ICO, COR also close 1co2 &c. and circuit is made over lr2 &c. to transmit relays 2HF, 2MF, 2LF(A) to connect the oscillators to, and retransmit the oscillating over, line 2. The receiving apparatus at station C corresponds to that of B and is shown in Figs. 4, 5, 6. The receivers, on receiving the signals, operate relays controlling shr, smr, slr, whereby X, W are operated to close CO to clear the normal control equipment from the line. X, Y, W close over w2, x2, y1 the circuit of RCR over 2b, rem, driving magnet RCM. Homing relay H also at h1 holds open the homing circuit of RCR during receipt of the signal. When the signals have all been received, the wipers are at position 6, and circuit is made over contacts h2, d4 for trip-coil of CB1, but if the wrong signals are received or the signals are received in the wrong order, RCR will be thrown out of step with the signalling conditions and fail to reach the tripping position. If CB2 is tripped, SB is operated to transmit code No. 2, N having first operated to change the connections of SND. Terminal points C, D (Fig. 6) are transposed if it is necessary to signal a station having a different identity frequency, this operating N which in turn operates LX and lx1 alters the tuning of the low oscillator. Intertripping between stations C, D is effected by one station transmitting directly to the other. The transmitting wipers are restored to home position at the twelfth contact where COA is operated over 1a, n3, sa4, and at coal releases SA, which at sa2 opens the driving circuit and completes over 5a a circuit for rotating the wipers to home position.